Two-motor co-located gimbal-based dual stage actuation disk drive suspensions with motor stiffeners

ABSTRACT

Various embodiments concern a dual stage actuation flexure. The dual stage actuation flexure comprises a flexure having a gimbal. The gimbal comprising a pair of spring arms, a tongue between the spring arms, and a pair of linkages respectively connecting the pair of spring arms to the tongue. The dual stage actuation flexure further comprises a pair of motors mounted on the gimbal and a pair of stiffeners respectively mounted on the motors. The dual stage actuation flexure further comprises a slider mounting. Electrical activation of the motors bends the pair of linkages to move the slider mounting about a tracking axis while the stiffeners limit the degree of bending of the motors during the electrical activation.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/826,865, filed May 23, 2013, which is herein incorporated byreference in its entirety and for all purposes.

TECHNICAL FIELD

The present invention relates to disk drives and suspensions for diskdrives. In particular, the invention is a dual stage actuation (DSA)suspension having a motor with a stiffener mounted thereon.

BACKGROUND

Dual stage actuation (DSA) disk drive head suspensions and disk drivesincorporating DSA suspensions are generally known and commerciallyavailable. For example, DSA suspensions having an actuation structure onthe baseplate or other mounting portion of the suspension, i.e.,proximal to the spring or hinge region of the suspension, are describedin the Okawara U.S. Patent Publication No. 2010/0067151, the Shum U.S.Patent Publication No. 2012/0002329, the Fuchino U.S. Patent PublicationNo. 2011/0242708 and the Imamura U.S. Pat. No. 5,764,444. DSAsuspensions having actuation structures located on the loadbeam orgimbal portions of the suspension, i.e., distal to the spring or hingeregion, are also known and disclosed, for example, in the Jurgenson U.S.Pat. No. 5,657,188, the Krinke U.S. Pat. No. 7,256,968 and the Yao U.S.Patent Publication No. 2008/0144225. Co-located gimbal-based DSAsuspensions are disclosed in co-pending U.S. Provisional ApplicationNos. 61/700,972 and 61/711,988. All of the above-identified patents andpatent applications are incorporated herein by reference in theirentirety and for all purposes.

There remains a continuing need for improved DSA suspensions. DSAsuspensions with enhanced performance capabilities are desired. Thesuspensions should be capable of being efficiently manufactured.

SUMMARY

Various embodiments concern a dual stage actuation flexure. The dualstage actuation flexure comprises flexure having a gimbal, the gimbalcomprising a pair of spring arms, a tongue between the spring arms, anda pair of linkages respectively connecting the pair of spring arms tothe tongue. The dual stage actuation flexure further comprises a pair ofmotors mounted on the gimbal, a pair of stiffeners respectively mountedon the motors, and a slider mounting. Electrical activation of themotors bends the pair of linkages to move the slider mounting about atracking axis while the stiffeners limit the degree of bending of themotors during the electrical activation. A slider is attached to theslider mounting.

In some configurations, the slider mounting is located on same side ofthe flexure as the motors, while in some other configurations the slidermounting is located on the opposite side of the flexure as the motors.

In some configurations, the tongue comprises a pair of first motormountings, the pair of motors respectively attached to the first motormountings. In some further configurations, the pair of linkagescomprises a pair of second motor mountings, the pair of motorsrespectively attached to the pair of second motor mountings. In somefurther configurations, each linkage of the pair of linkages comprises astrut. Electrical activation of the motor bends the struts to move theslider mounting about the tracking axis.

In some configurations, each stiffener is bonded to a respective one ofthe motors by a respective layer of adhesive that is between the motorand the stiffener. In some configurations, at least one of thestiffeners is asymmetric with respect to one or both of a longitudinalaxis of the stiffener and a transverse axis of the stiffener.

Some configurations further comprise an additional pair of stiffenersrespectively mounted on the motors, wherein the stiffeners arerespectively mounted on the top sides of the motors and the additionalpair of stiffeners are respectively mounted on the bottom sides of themotors.

Various embodiments concern a dual stage actuation flexure. The dualstage actuation flexure comprises flexure having a pair of spring arms,a pair of struts, and a tongue between the spring arms. The dual stageactuation flexure further comprises a pair of motors mounted on theflexure, each motor comprising a top side and a bottom side opposite thetop side. The dual stage actuation flexure further comprises a pair ofstiffeners respectively mounted on the top sides of the motors, adhesivelocated between the stiffeners and the motors and bonded to thestiffeners and the motors, and a slider mounting. Electrical activationof the motors bends the pair of struts to move the slider mounting whilethe stiffeners limit the degree of bending of the motors during theelectrical activation.

Various embodiments concern a dual stage actuation flexure. The dualstage actuation flexure comprises flexure, a pair of motors mounted onthe flexure, a pair of stiffeners respectively mounted on the motors,adhesive located between the stiffeners and the motors and bonded to thestiffeners and the motors, and a slider mounting. Electrical activationof the motors moves the slider mounting while the stiffeners limit thedegree of bending of the motors during the electrical activation.

Further features and modifications of the various embodiments arefurther discussed herein and shown in the drawings. While multipleembodiments are disclosed, still other embodiments of the presentdisclosure will become apparent to those skilled in the art from thefollowing detailed description, which shows and describes illustrativeembodiments of this disclosure. Accordingly, the drawings and detaileddescription are to be regarded as illustrative in nature and notrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of the loadbeam side of a suspension havinga flexure with a dual stage actuation (DSA) structure.

FIG. 2 is an isometric view of the loadbeam side of the distal end ofthe suspension shown in FIG. 1.

FIG. 3 is an isometric view of the flexure side (i.e., the side oppositethat shown in FIG. 2) of the distal end of the suspension shown in FIG.1.

FIG. 4A is an isometric view of the stainless steel side of the flexureshown in FIG. 1.

FIG. 4B is the view of FIG. 4A but with the piezoelectric motor removed.

FIG. 5A is an isometric view of the trace side (i.e., the side oppositethat shown in FIG. 4A) of the flexure shown in FIG. 1.

FIG. 5B is the view of FIG. 5A but with the head slider removed.

FIG. 5C is the view of FIG. 5B but with the polyimide coverlay removed.

FIG. 5D is the view of FIG. 5C but with the conductive material layerremoved.

FIG. 5E is the view of FIG. 5D but with the dielectric material layerremoved.

FIG. 5F is the view of FIG. 5E but with the piezoelectric motor removed.

FIG. 6 is a side view of the distal end of the suspension shown in FIG.1.

FIG. 7 is a closer view of the portion of FIG. 6 showing the dimple,motor, and head slider.

FIGS. 8A-8C are plan views of the stainless steel side of the flexureshown in FIG. 1, illustrating the operation of the DSA structure.

FIG. 9 is an isometric view of the loadbeam side of a suspension havinga flexure with a dual stage actuation (DSA) structure.

FIG. 10 is an isometric view of the loadbeam side of the distal end ofthe suspension shown in FIG. 9.

FIG. 11 is an isometric view of the flexure side (i.e., the sideopposite that shown in FIG. 10) of the distal end of the suspensionshown in FIG. 9.

FIG. 12 is an isometric view of the stainless steel side of the flexureshown in FIG. 9.

FIG. 13A is an isometric view of the trace side (i.e., the side oppositethat shown in FIG. 12) of the flexure shown in FIG. 9.

FIG. 13B is the view of FIG. 13A but with the head slider removed.

FIG. 13C is the view of FIG. 13B but with the motor removed.

FIG. 13D is the view g of FIG. 13C but with the coverlay removed.

FIG. 13E is the view of FIG. 13D but with the conductive material layerremoved.

FIG. 13F is the view of FIG. 13E but with the dielectric material layerremoved.

FIG. 14 is a side view of the distal end of the suspension shown in FIG.9.

FIG. 15 is a closer view of the portion of FIG. 14 showing the dimple,motor, and head slider.

FIGS. 16A ₁, 16B₁, and 16C₁ are plan views of the stainless steel sideof the flexure shown in FIG. 9.

FIGS. 16A ₂, 16B₂, and 16C₂ are plan views of the trace side of theflexure shown in FIGS. 16A ₁, 16B₁, and 16C₁, respectively.

FIG. 17 is an isometric view of a tri-stage actuated suspension.

FIG. 18 is an isometric view of the stainless steel side of the distalend of a flexure having a DSA structure with a stiffener.

FIG. 19 is a side view of the distal end of the flexure shown in FIG.18.

FIG. 20 is an illustration of the flexure shown in FIG. 18 when themotor is actuated into an expanded state.

FIG. 21 is an illustration of the flexure shown in FIG. 18 when themotor is actuated into a contracted state.

FIG. 22 is an isometric view of the stainless steel side of the distalend of a flexure having a DSA structure with an asymmetric stiffener.

FIG. 23 is an illustration of the flexure shown in FIG. 22 when themotor is actuated into a contracted state.

FIG. 24 is an illustration of the flexure shown in FIG. 22 when themotor is actuated into an expanded state.

FIG. 25 is an isometric view of the stainless steel side of the distalend of a flexure having a DSA structure with a stiffener and multipleadhesives.

FIG. 26 is a distal end view of the flexure shown in FIG. 25.

FIG. 27 is an illustration of the flexure shown in FIG. 25 when themotor is actuated into an expanded state.

FIG. 28 is an isometric view of the stainless steel side of the distalend of a flexure having a DSA structure with a multiple thicknessstiffener attached to the motor with multiple adhesives.

FIG. 29 is a detailed side view of the distal end of the flexure shownin FIG. 28.

FIG. 30 is an isometric view of the stainless steel side of the distalend of a flexure having a DSA structure with an asymmetric stiffenerattached to the motor with multiple adhesives.

FIG. 31 is an isometric view of the stainless steel side of the distalend of a flexure having a DSA structure with an asymmetric stiffener.

FIGS. 32A and 32B are illustrations of the flexure shown in FIG. 31 whenthe motor is actuated into contracted and expanded states, respectively.

FIG. 33A is an isometric view of the trace side of flexure having atwo-motor DSA structure with stiffeners.

FIG. 33B is an isometric view of the stainless steel side of the flexureshown in FIG. 33A.

FIG. 34A is a plan views of the trace side of the flexure shown in FIG.33A in a non-actuated state.

FIG. 34B is a plan views of the trace side of the flexure shown in FIG.34A in an actuated state.

FIG. 35A is an isometric view of the trace side of flexure having atwo-motor DSA structure with stiffeners.

FIG. 35B is an isometric view of the stainless steel side of the flexureshown in FIG. 35A.

FIG. 36A is an isometric view of the trace side of flexure having atwo-motor DSA structure with stiffeners.

FIG. 36B is an isometric view of the stainless steel side of the flexureshown in FIG. 35A.

FIG. 37 is an isometric view of the trace side of the flexure shown inFIG. 35A with the motors removed.

FIG. 38A is an isometric view of the trace side of flexure having atwo-motor DSA structure with stiffeners.

FIG. 38B is an isometric view of the stainless steel side of the flexureshown in FIG. 38A.

DESCRIPTION OF THE INVENTION

FIG. 1 is an isometric view of the loadbeam side of a suspension 10having a flexure 12 with a co-located or gimbal-based dual stageactuation (DSA) structure 14 in accordance with a first embodiment ofthis disclosure (i.e., a stainless steel side version). FIG. 2 is adetailed isometric view of the distal end of the suspension 10. FIG. 3is a detailed isometric view of the flexure side of the distal end ofthe suspension 10, which shows the side opposite that shown in FIG. 2.As shown in FIG. 1, the suspension 10 includes a baseplate 16 as aproximal mounting structure. As further shown in FIG. 1, the suspension10 includes a loadbeam 18 having a rigid or beam region 20 coupled tothe baseplate 16 along a spring or hinge region 22. The loadbeam 18 canbe formed from stainless steel.

Flexure 12 includes a gimbal 24 at the distal end of the flexure 12. ADSA structure 14 is located on the gimbal 24, adjacent the distal end ofthe loadbeam 18. As best shown in FIG. 2, the suspension 10 includes agimbal limiter 26 comprising a tab 28 configured to engage a stopportion 30 of the loadbeam 18. A head slider 32 is mounted to a slidermounting or tongue 33 of the gimbal 24, on the side of the suspension 10that is opposite the loadbeam 18. DSA structure 14 includes a motor 34,which is a PZT or other piezoelectric actuator in the illustratedembodiment, mounted to the gimbal 24 of the flexure 12 between theloadbeam 18 and the head slider 32. As described in greater detailbelow, in response to electrical drive signals applied to the motor 34,the motor drives portions of the gimbal 24, including the tongue 33 andslider 32, about a generally transverse tracking axis. Proximal anddistal, as used herein, refers to the relative direction along thelongitudinal axis of the suspension while lateral refers to the leftand/or right directions orthogonal to the longitudinal axis of thesuspension. For example, the baseplate 16 is proximal of the loadbeam 18while opposite ends of the motor 34 extend laterally.

FIGS. 4A and 4B are isometric views of the stainless steel side of theflexure 12 and DSA structure 14 shown in FIG. 1. The motor 34 is notshown in FIG. 4B to show further details of the tongue 33. FIGS. 5A-5Fare isometric views of the trace side (i.e., the side opposite thatshown in FIGS. 4A and 4B) of the flexure 12 and DSA structure 14.Specifically, FIGS. 5A-5F show the various layers that comprise theflexure 12 and DSA structure 14. FIG. 5B is the drawing of FIG. 5A butwith the head slider 32 removed to further show details of the tongue33. FIG. 5C is the drawing of FIG. 5B but with a polyimide coverlay 46removed to reveal a conductive material layer 44 including traces 60 andother structures formed in the conductive material layer that isotherwise underneath the polyimide coverlay 46. FIG. 5D is the drawingof FIG. 5C but with the conductive material layer 44 removed to morefully reveal the dielectric layer 42 that is otherwise underneath theconductive material layer 44. FIG. 5E is the drawing of FIG. 5D but withthe dielectric layer 42 removed to show only the stainless steel layer40 and the motor 34. FIG. 5F is the drawing of FIG. 5E but with themotor 34 removed to illustrate only the stainless steel layer 40 of theflexure 12. It will be understood that the stainless steel layer 40could alternatively be formed from another metal or rigid material.

As shown in FIGS. 5A-5F, the flexure 12 is formed from overlaying springmetal such as stainless steel layer 40, polyimide or other dielectriclayer 42, copper or other conductive material layer 44 and polyimidecoverlay 46. The dielectric layer 42 generally electrically isolatesstructures formed in the conductive material layer 44 from adjacentportions of the stainless steel layer 40. Coverlay 46 generally coversand protects the structures formed in the conductive material layer 44.The gimbal 24 includes the spring arms 52 and the tongue 33. The springarms 52 extend from the base portion 50. The slider mounting 54, whichis part of the tongue 33, is supported between the spring arms 52 by apair of struts 56 that extend from support regions 58 on the distal endportions of the spring arms 52. The slider 32 can be attached to thetongue 33 along the slider mounting 54 (e.g., by adhesive). In someembodiments, the pair of struts 56 is the only part of the stainlesssteel layer 40 that connects or otherwise supports the tongue 33 betweenthe spring arms 52. Specifically, the struts 56 can be the onlystructural linkage between the spring arms 52 and the tongue 33. Also,the struts 56, in connecting with the tongue 33, can be the only part ofthe stainless steel layer 40 that connects between the spring arms 52distal of the base portion 50. As shown, the struts 56 are offset fromone another with respect to the longitudinal axis of the flexure 12 orotherwise configured so as to provide for rotational movement of theslider mounting 54 about the tracking axis with respect to the springarms 52. As best shown in FIG. 8B (further discussed herein), one strut56 of the pair of struts 56 is located proximally of the motor 34 whilethe other strut 56 of the pair of struts 56 is located distally of themotor 34 such that the motor 34 is between the pair of struts 56. Eachstrut 56 has a longitudinal axis that extends generally perpendicularwith respect to the longitudinal axis of the suspension 10. Thelongitudinal axes of the struts 56 extend parallel but do not intersector otherwise overlap with each other when the struts 56 are not stressed(e.g., not bent). As shown in FIG. 5F, the struts 56 can each be thenarrowest part of the stainless steel layer 40 in an X-Y plane (asviewed from the overhead perspective of FIG. 8B) while the thickness ofthe stainless steel layer 40 can be consistent along the flexure 12.

As perhaps best shown in FIGS. 4A and 5E, the opposite ends of the motor34 are attached (e.g., by structural adhesive such as epoxy) to thesupport regions 58 of the spring arms 52. In this way, the supportregions 58 can serve as motor mounting pads. Portions of the dielectriclayer 42 extend underneath the struts 56 in FIG. 4B. As shown in FIG.5C, a plurality of traces 60 formed in the conductive material layer 44extend between the base portion 50 and the tongue 33 along the flexiblecircuit 62 formed in the dielectric layer 42. A number of the traces 60terminate at locations on a distal region on the tongue 33 and areconfigured to be electrically attached to terminals of the read/writehead (not shown) on the slider 32. Other traces 60 terminate at acontact such as copper pad 64 on the tongue 33, below the motor 34. Inthe illustrated embodiment, the copper pad 64 is located generallycentrally between the spring arms 52. As perhaps best shown in FIG. 4B,the dielectric layer 42 has an opening over the pad 64. A structural andelectrical connection, e.g., using conductive adhesive, is made betweenthe copper pad 64 and an electrical terminal on the motor 34. Anotherelectrical connection to a terminal on the motor 34 (e.g., a groundterminal) is made through the dimple 36 (i.e., the dimple 36 is inelectrical contact with the terminal on the motor 34). In otherembodiments, the electrical connections to the motor 34 can be made byother approaches and structures.

As shown in FIGS. 5A and 5B, the slider 32 sits on the coverlay 46 ofthe tongue 33. Coverlay 46 provides protection for the traces 60. Asshown in FIGS. 5A-5C, which show that portions of the flexible circuit62 are offset with respect to the longitudinal direction of the flexure12, portions of the traces 60 on the opposite sides of the flexure 12are offset from each other in a manner similar to that of the struts 56(e.g., portions of the traces overlay the struts in the illustratedembodiment). Offset traces of this type can increase the strokeperformance of the DSA structure 14. Various other embodiments (notshown) do not have offset traces. It is noted that, in some embodiments,the flexible circuit 62 may provide negligible mechanical support to thetongue 33 relative to the struts 56.

FIGS. 6 and 7 are side views of the suspension 10, illustrating thegimbal 24 and DSA structure 14. As shown, the dimple 36, which is astructure formed in the stainless steel material that forms the loadbeam18, and which extends from the loadbeam 18, engages the motor 34 andfunctions as a load point by urging the portion of the gimbal 24 towhich the motor 34 is connected out of plane with respect to the baseportion 50 of the flexure 12. A bend or transition in the flexure 12 canoccur at any desired location along the spring arms 52 due to the urgingof the gimbal 24 by the dimple 36. The dimple 36 can also provide anelectrical contact to a terminal (not visible) on the portion of themotor 34 engaged by the dimple. For example, if the stainless steelloadbeam 18 is electrically grounded or otherwise part of an electricalcircuit, the dimple 36 can provide an electrical ground potential orelectrical connection to the terminal on the motor 34. Various otherembodiments (not shown) include other dimple structures such as platedstructures that provide these functions. The dimple 36 can be platedwith conductive material such as gold to enhance the electricalconnection to the terminal of the motor 34 which can also be plated withconductive material such as gold. Still other embodiments (not shown)use structures other than the dimple 36 to provide a grounding or otherelectrical connection to the motor 34. In one such embodiment, forexample, there is another copper pad on the end of one of the supportregions 58, and an electrical connection (e.g., a ground connection) canbe made by a structure such as conductive adhesive between a terminal onthe motor 34 and the conductive material pad on the support region ofthe flexure 12. In some embodiments, the motor 34 is structurallyattached to the tongue 33 at a location between the opposite lateral endportions of the tongue 33. In such embodiments, the motor 34 is attachedto the tongue 33 of the gimbal 24 in addition to the motor 34 beingattached to the support regions 58 of the spring arms 52.

The operation of DSA structure 14 can be described with reference toFIGS. 8A-8C that are plan views of the stainless steel side of thegimbal 24 of the flexure 12. As shown in FIG. 8B, the DSA structure 14and tongue 33 are in a neutral, undriven state with the tongue 33generally centrally located between the spring arms 52 when no trackingdrive signal is applied to the motor 34. As shown in FIG. 8A, when afirst potential (e.g., positive) tracking drive signal is applied to themotor 34, the shape of the motor changes and its length generallyexpands. This change in shape increases the distance between the supportregions 58 as shown in FIG. 8A, which in connection with the mechanicalaction of the linking struts 56, causes the tongue 33 to move or rotatein a first direction with respect to the spring arms 52 about thetracking axis. As shown, the lengthening of the motor 34 stretches thegimbal 24 laterally and causes the struts 56 to bend (e.g., bow inward).Because of the offset arrangement of the struts 56, the struts 56 bendsuch that the tongue 33 rotates in the first direction.

As shown in FIG. 8C, when a second potential (e.g., negative) trackingdrive signal is applied to the motor 34, the shape of the motor changesand its length generally contracts. This change in shape decreases thedistance between the support regions 58 as shown in FIG. 8C, which inconnection with the mechanical action of the linking struts 56, causesthe tongue 33 to move or rotate in a second direction with respect tothe spring arms 52 about the tracking axis. The second direction isopposite the first direction. As shown, the shortening of the motor 34compresses the gimbal 24 laterally and causes the struts 56 to bend(e.g., bow outward). Because of the offset arrangement of the struts 56,the struts 56 bend such that the tongue 33 rotates in the seconddirection. Some, although relatively little, out-of-plane motion ofother portions of the gimbal 24 is produced during the tracking actionof DSA structure 14 as described above. With this embodiment of thisdisclosure, slider mounting on the tongue 33 generally rotates withrespect to the spring arms 52 as the spring arms 52 stay stationary orexperience little movement.

FIG. 9 is an isometric view of the loadbeam-side of a suspension 110having a flexure 112 with a co-located or gimbal-based dual stageactuation (DSA) structure 114 in accordance with a second embodiment ofthis disclosure (i.e., a trace side version). The components of thesuspension 110 can be configured similarly to the previously discussedsuspension 10 unless otherwise described or illustrated. FIG. 10 is anisometric view of the distal end of the suspension 110. FIG. 11 is anisometric view of the flexure-side of the distal end of the suspension110, showing the side opposite that shown in FIG. 10. As shown in FIG.10, the suspension 110 includes a baseplate 116 as a proximal mountingstructure. As further shown in FIG. 11, the suspension 110 includes aloadbeam 118 having a rigid or beam region 120 coupled to the baseplate116 along a spring or hinge region 122. The loadbeam 118 can be formedfrom stainless steel. Flexure 112 includes a gimbal 124 at its distalend. A DSA structure 114 is located on the gimbal 124, adjacent thedistal end of the loadbeam 118. The illustrated embodiment of thesuspension 110 also includes a gimbal limiter 126 comprising a tab 128configured to engage a stop portion 130 of the loadbeam 118. The DSAstructure 114 includes a motor 134, which is a PZT actuator in theillustrated embodiment, mounted to a motor mounting region of the tongue133, on the side of the flexure 112 opposite the loadbeam 118. A headslider 132 is mounted to the side of the motor 134 opposite the flexure112. As described in greater detail below, in response to electricaldrive signals applied to the motor 134, the motor drives portions of thegimbal 124, including portions of the tongue 133, motor 134 and slider132, about a generally transverse tracking axis.

FIG. 12 is a detailed isometric view of the stainless steel-side of theflexure 112 and DSA structure 114 shown in FIG. 9. FIGS. 13A-13F areisometric views of the flexure 112 and DSA structure 114 showing theside opposite that shown in FIG. 12. Specifically, FIGS. 13A-13F showthe various layers that comprise the flexure 112 and DSA structure 114.FIG. 13B is the drawing of FIG. 13A but with the head slider 132 removedto further show details of the motor 134 on the tongue 133. FIG. 13C isthe drawing of FIG. 13B but with the motor 134 removed to reveal detailsof the tongue 133. FIG. 13D is the drawing of FIG. 13C but with thecoverlay 146 removed to reveal a conductive material layer 144 includingtraces 160 and other structures formed in the conductive material layer144. FIG. 13E is the drawing of FIG. 13D but with the conductivematerial layer 144 removed to further reveal the dielectric layer 142.FIG. 13F is the drawing of FIG. 13E but with the dielectric layer 142removed to show only the stainless steel layer 140 of the flexure 112.It will be understood that the stainless steel layer 140 couldalternatively be formed from another metal or rigid material. As shown,the flexure 112 is formed from overlaying spring metal such as stainlesssteel layer 140, polyimide or other dielectric layer 142, copper orother conductive material layer 144, and coverlay 146. The dielectriclayer 142 generally electrically isolates structures formed in theconductive material layer 144 from adjacent portions of the stainlesssteel layer 140. Coverlay 146 generally covers and protects thestructures formed in the conductive material layer 144.

The gimbal 124 includes spring arms 152 and the tongue 133. The baseportion 150, the spring arms 152, and the center region 154 are eachformed from the stainless steel layer 140. The spring arms 152 extendfrom the base portion 150. The center region 154, which is a center partof the tongue 133, is connected to the distal ends of the spring arms152 and is supported between the spring arms 152. Also formed in thestainless steel layer 140 is a pair of struts 153. Each of the struts153 extends from one of the opposite lateral sides of the center region154 and has a motor mounting flag or pad 155 on its outer end. As shown,the struts 153 are offset from one another with respect to thelongitudinal axis of the flexure 112 or otherwise configured so as toprovide for rotational movement of the motor 134 and the head slider 132mounted thereto about the tracking axis with respect to the centerregion 154. Each strut 153 comprises a longitudinal axis that extendsgenerally perpendicular with respect to the longitudinal axis of thesuspension 110. The longitudinal axes of the struts 153 extend parallelbut do not intersect or otherwise overlap with each other when thestruts 153 are not stressed (e.g., not bent). The struts 153 can be theonly structural linkage between the center region 154 and the pads 155(e.g., the only part of the stainless steel layer 140 connecting thecenter region 154 with the pads 155 is the struts 153, a single strut153 for each pad 155). As shown in FIG. 13F, the struts 153 can each bethe narrowest part of the stainless steel layer 140 in an X-Y plane (asviewed from the overhead perspective of FIG. 16B ₁) while the thicknessof the stainless steel layer 140 can be consistent along the flexure112.

As shown in FIG. 13D, a plurality of traces 160 are formed in theconductive material layer 144 and extend between the base portion 150and tongue 133 along paths generally laterally outside the spring arms152 and along the flexible circuit 162 formed in the dielectric layer142. A number of the traces 160 terminate at locations adjacent thedistal region of the tongue 133 and are configured to be electricallyattached to read/write head terminals (not shown) on the slider 132. Apair of power traces 161 for powering the motor 134 are also formed inthe conductive material layer 144, and extend between the base portion150 and a proximal portion of the tongue 133 along paths generallyinside the spring arms 152 and along the flexible circuit 163 formed inthe dielectric layer 142. The motor power traces 161 terminate at afirst motor terminal pad 167 on one of the motor mounting pads 155. Asecond motor terminal pad 169 is formed in the conductive material layer144 on the other motor mounting pad 155, and is coupled by a trace 171to a conductive via 173 that is shown on the tongue 133 at a locationbetween the motor mounting pads 155. As best viewed in FIG. 13D, via 173extends through an opening 175 in the dielectric layer 142 (shown inFIG. 13E) to electrically contact the stainless steel layer 140 of theflexure 112. The motor terminal pad 169 can be electrically connected toa ground potential at the stainless steel layer 140 by the trace 171 andthe via 173. As shown in FIG. 12, structures such as tabs 157 in thestainless steel layer 140 are formed out of the plane of the stainlesssteel layer and engage the distal portion of the trace flexible circuit162 to push the terminal ends of the traces 161 down so the terminals onthe slider 132 can be correctly electrically attached (e.g., by solderbonds) to the traces while accommodating the thickness of the motor 134.FIG. 13E also illustrates other holes in the dielectric layer that canbe used in connection with conductive vias to electrically connect(e.g., ground) traces and other structures in the conductive materiallayer 144 to the stainless steel layer 140. In other embodiments, otherapproaches and structures can be used to couple the tracking drivesignals to the terminals on the motor 134.

The electrical terminals on the motor 134 may be on the same side (e.g.,top or bottom) but opposite longitudinal ends of the motor 134. As shownin FIGS. 13B and 13C, the motor 134 can be attached to the gimbal 124 bybonding the electrical terminals of the motor 134 to the motor terminalpads 167 and 169 using conductive adhesive. By this approach, the motor134 is both structurally and electrically connected to the gimbal 124.As shown in FIG. 13C, the motor terminal pads 167 and 169 are exposedthrough openings in the coverlay 146 to provide access for theconductive adhesive.

FIGS. 14 and 15 are side views of the suspension 110, illustrating thegimbal 124 and DSA structure 114. As shown, the dimple 136, which is astructure formed in the stainless steel of the loadbeam 118 and whichprojects from the loadbeam 118, engages the center region 154 ofstainless steel layer 140 on the side of the tongue 133 opposite themotor 134. Dimple 136 functions as a load point by urging the portion ofthe gimbal 124 to which the motor 134 is connected out of plane withrespect to the base portion 150 of the flexure 112. In the illustratedembodiment, the motor 134 is located between the tongue 133 and the headslider 132 (e.g., the motor 134 is sandwiched in a vertical axis). Asshown in FIGS. 14 and 15, the slider 132 is structurally supported bythe motor 134 such that the only structural linkage between the flexure112 and the slider 132 runs through or otherwise includes the motor 134.The manner by which the stainless steel tabs 157 locate the portion ofdielectric layer 142 with the terminal ends of the traces 160 at thecorrect z-height and adjacent to the portion of the head slider 132 thatincludes the read/write head terminals is shown in FIG. 15.

The operation of DSA structure 114 can be described with reference toFIGS. 16A ₁, 16A₂, 16B₁, 16B₂, 16C₁ and 16C₂ that are plan views of thegimbal 124 of the flexure 112. FIGS. 16A ₁, 16B₁ and 16C₁ illustrate thestainless steel side of the flexure 112, and FIGS. 16A ₂, 16B₂ and 16C₂illustrate the trace side of the flexure 112, with the motor 134 andhead slider 132 shown. As shown in FIGS. 16B ₁ and 16B₂, the DSAstructure 114 and tongue 133, as well as the motor 134 on the linkageformed by the motor mounting pads 155 and struts 153, are in a neutral,undriven state with the head slider positioned generally parallel to thelongitudinal axis of the flexure 112 when no tracking drive signal isapplied to the motor 134. The struts 153 are not bent or otherwisestressed in this state. As shown in FIGS. 16A ₁ and 16A₂, when a firstpotential (e.g., positive) tracking drive signal is applied to the motor134, the shape of the motor changes and its length generally expands.This change in shape increases the distance between the motor mountingpads 155, which in connection with the mechanical action of the linkingstruts 153, causes the motor 134, and therefore the head slider 132mounted thereto, to move or rotate in a first direction with respect tothe longitudinal axis of the flexure 112 about the tracking axis. Asshown, the lengthening of the motor 134 stretches the struts 153laterally and causes the struts 153 to bend (e.g., bow inward). Becauseof the offset arrangement of the struts 153, the struts 153 bend suchthat the motor 134 and the head slider 132 rotate in the firstdirection.

As shown in FIGS. 16C ₁ and 16C₂, when a second potential (e.g.,negative) tracking drive signal is applied to the motor 134, the shapeof the motor changes and its length generally contracts. This change inshape decreases the distance between the motor mounting pads 155, whichin connection with the mechanical action of the linkage including struts153, causes the motor 134, and therefore the head slider 132 mountedthereto, to move or rotate in a second direction with respect to thelongitudinal axis of the flexure 112 about the tracking axis. The seconddirection is opposite the first direction. As shown, the shortening ofthe motor 134 compresses the struts 153 laterally and causes the struts153 to bend (e.g., bow outward). Because of the offset arrangement ofthe struts 153, the struts 153 bend such that the motor 134 and the headslider 132 rotate in the second direction.

Some, although relatively little, out-of-plane motion of other portionsof the gimbal 124 may be produced during the tracking action of DSAstructure 114. The linkage provided by the struts 153 accommodates themotion of the motor 134 so the remaining portions of the tongue 133remain generally aligned with respect to the longitudinal axis of theflexure 112 during this tracking action. For example, the motor 134 andslider 132 rotate, but the center region 154 (or more broadly the tongue133) does not rotate or rotates only an insignificant or trivial amount.

FIG. 17 is an illustration of a suspension 210 in accordance withanother embodiment of this disclosure. As shown, the suspension 210includes a co-located or gimbal-based DSA structure 214 and a loadbeamor baseplate-type DSA structure 290. In this way, the suspension 210 isa tri-stage actuated suspension. In one embodiment, the DSA structure214 is substantially the same as the DSA structure 114 described above(e.g., is configured with any aspect described or shown in connectionwith FIGS. 9-16C ₂) except as otherwise specified or shown. In anotherembodiment, the DSA structure 214 is substantially the same as the DSAstructure 14 described above (e.g., is configured with any aspectdescribed or shown in connection with FIGS. 1-8C) except as otherwisespecified or shown. Other embodiments of suspension 210 include othergimbal-based DSA structures. The DSA structure 290 can be any known orconventional DSA structure such as any of those described above in thebackground section.

Bowing, twisting, and/or asymmetric bending can be present in varioussuspensions such as those described above. For example, returning thesuspension of FIGS. 1-8C, when the motor 34 on the suspension 10 isactuated to expand, the motor 34 can vertically deflect by bowing suchthat the lateral ends of the motor 34 move toward the slider 32 and thestainless steel layer 40 of the gimbal 24 relative to the middle of themotor 34. In other words, upon expansion, the lateral ends of the motor34 bend downward and/or the middle of the motor 34 bends upwards. Thedeflection of the motor 34 in this manner can be due to the resistanceprovided by the gimbal 24. For example, the gimbal 24, being on one sideof the motor 34 while the other side of the motor 34 is unrestrained,resists the expansion of the motor 34 and therefore causes the motor 34,along with the attached gimbal 24, to vertically deflect. Conversely,when the motor 34 is electrically activated with the opposite polarityto contract, the motor 34 can deflect by bowing in the oppositedirection such that the lateral ends of the motor 34 move away theslider 32 and the stainless steel layer 40 of the gimbal 24 relative tothe middle of the motor 34 which moves toward the slider 32 and thestainless steel layer 40. In other words, upon expansion, the lateralends of the motor 34 bend upward and/or the middle of the motor 34 bendsdownwards. The deflection of the motor 34 in this manner can likewise bedue to the resistance provided by the gimbal 24 on one side of the motor34. The vertical direction of this bending can reduce stroke efficiencyof the motor 34. For example, the motor 34 cannot fully extend orcontract along its longitudinal axis when also bending in a verticaldirection, and as such some stroking range is lost. Furthermore, themotor 34 can twist about its longitudinal axis (typically transverselyoriented on the gimbal 24) during expansion and contraction. This twistcan be due to asymmetric bending stiffness of the offset gimbal struts56. Asymmetric bending and twisting can also lead to increased gimbalmodes (natural frequencies) causing resonance performance issues.Reduced resonance performance can lead to lower servo bandwidth in thedisk drives into which the suspensions are incorporated. This, in turn,can increase the distance that the individual tracks are spaced fromeach other on the disks, and thereby reduce the overall amount of datathat can be packed onto the disk surface.

Various embodiments of this disclosure include a stiffener componentthat is bonded or otherwise attached to a side (e.g., a top or freeside) of a motor. Such a stiffener can limit the bending of the motorand/or gimbal during motor activation. FIGS. 18-32B show variousembodiments of suspensions having a stiffener mounted on a motor toaddress the issues discussed above.

FIG. 18 is an isometric view of the stainless steel side of a flexure212. FIG. 19 is a side view of the flexure 212. The flexure 212 is partof a DSA structure 214 that can be similar to that of the DSA structure14 described above or other DSA structure referenced herein except wherenoted. Features of flexure 212 that are the same or similar to those offlexure 12 are indicated by similar reference numbers. A stiffener 280is mounted on the motor 234. The stiffener 280 is attached to the motor234 by adhesive 282 disposed between the stiffener 280 and the motor234. Specifically, the adhesive 282 can be a layer of adhesive that isbonded to a bottom side of the stiffener 280 and a top side of the motor234. In the embodiment shown in FIG. 18, the stiffener 280 is locatedover the entire top or free surface of the motor 234 (i.e., the surfaceof the motor 234 that is opposite the bottom side of the motor 234 thatfaces the tongue 233). As shown, the four edges (lateral sides, front,and back) of the stiffener 280 are aligned with the four edges (lateralsides, front, and back) of the motor 234.

The stiffener 280 will generally have sufficient stiffness to at leastpartially offset the stiffness of the portion of gimbal 224 that isresisting motion of the motor 234 and causing the stroke-reducingbending. In some embodiments, the stiffener 280 is made from metal suchas stainless steel, aluminum, nickel, titanium or other structuralmetal. In various other embodiments, the stiffener 280 is formed from apolymer material. A polymer stiffener may have increased thickness (ascompared to a metal stiffener) to provide the desired bending stiffness.The stiffener 280 can, for example, be etched, cut or otherwise formedfrom sheet or film stock. In some embodiments, the stiffener 280 can beabout 10-25 μm in thickness. The stiffener can be thicker or thinner inother embodiments.

The embodiment of FIG. 18 further includes a reduced thickness region284 at the center of the stiffener 280. In this or in other ways, astiffener can have a first thickness along a first portion of thestiffener and a second thickness along a second portion of thestiffener, the second thickness less than the first thickness. Thereduced thickness region 284 can be a surface of the stiffener 280 thatis positioned and configured to make contact with a load point dimple ofthe loadbeam (not shown). Reducing the thickness of the stiffener 280 atthe dimple contact location can allow the dimple to extend into thecavity created by the reduced thickness region 284, which reduces theoverall height of the suspension 210 because the loadbeam can be closerto the flexure 212. Various other embodiments do not include the partialthickness region 284. Other configurations for a reduced thicknessregion are further discussed herein.

Adhesive 282 forms a relatively thin material layer between the motor234 and stiffener 280 (e.g., about 2-25 μm in some embodiments). In someembodiments, the adhesive 282 has a relatively low elastic modulus toenhance the operation of the DSA structure 214. Low elastic modulusadhesives 282 can provide reduced resistance of the stiffener 280 onexpansion and contraction of the motor 234, while still enhancing thebending stiffness of the DSA structure 214. Embodiments of flexure 212with adhesive 282 having an elastic modulus of about 100 MPa havedemonstrated enhanced performance. Other embodiments can have adhesive282 with a different elastic modulus.

The motor 234 is mounted on the flexure 212 by being connected to a pairof connectors 245. The connectors 245 can connect with respective anodeand cathode terminals of the motor 234. The connectors 245 can furtherconnect with respective traces running along the flexure 212 toelectrically activate the motor 234. The connectors 245 can comprisesolder, conductive epoxy (e.g., silver filled), or other material forforming an electrode connection. The connectors 245 can structurallyattach the motor 234 to the flexure 212. Specifically, the pair ofconnectors 245 can connect the lateral ends of the motor 234 to the pairof spring arms 252, respectively. The slider 232 is mounted to a slidermounting of the tongue 233. The slider mounting is a surface of thetongue 233 to which the slider 232 can be attached, such as with anadhesive such as epoxy. Rotation of the tongue 333 by actuation of themotor 234 rotates the slider mounting, and thereby the slider 332, abouta tracking axis.

FIG. 20 is an isometric view of the flexure 212 and shows an example ofa state of the flexure 212 when the motor 234 is electrically activatedto expand to an expanded state. As shown, the motor 234 bends toward thestiffener 280 (i.e., in the direction opposite of the bending inembodiments of the same flexure 212 when the motor 234 expands withoutthe stiffener 280) such that the lateral ends of the motor 234 move awayfrom the slider 232 and the stainless steel layer 240 relative to themiddle of the motor 234 which moves toward the slider 232 and thestainless steel layer 240. In other words, upon expansion whilerestrained by the stiffener 280, the lateral ends of the motor 234 bendupward while the middle of the motor 234 bends downwards, which is theopposite bending profile had the stiffener 280 not been attached to themotor 234. Conversely, FIG. 21 is the same isometric view of the flexure212 as FIG. 20 when the motor 234 is electrically activated to contract.As shown, the motor 234 bends away the stiffener 280 (i.e., in thedirection opposite of the bending in embodiments of the same flexure 212when the motor 234 contacts without the stiffener 280) such that thelateral ends of the motor 234 move toward the slider 232 and thestainless steel layer 240 relative to the middle of the motor 234 whichmoves away the slider 232 and the stainless steel layer 240. In otherwords, upon contraction while restrained by the stiffener 280, thelateral ends of the motor 234 bend downward while the middle of themotor 234 bends upwards, which is the opposite bending profile had thestiffener 280 not been attached to the motor 234. However, it is notedthat not all embodiments are so limited and that the stiffener 280 canchange the bending profile of the flexure 212 in additional oralternative ways.

It is noted that the presence of the stiffener 280 on the motor 234 canchange the amount of deflection of the motor 234 when contracted. Thisbending action is produced because the overall stiffness of thestiffener 280 and motor 234 is stronger than the stiffness of theassociated portion of the flexure 212 (e.g., the stainless steel layer240 specifically) on the other side of the motor 234 with respect to thestiffener 280. In this way, the stiffener 280 can balance or counteractthe stiffness of the flexure 212 about the motor 234 to control or limitvertical deflection. Limiting the vertical deflection increases thestroke because the motor 234 is allowed to more fully expand or contractalong an axis that pushes or pulls the areas at which the motor 234 isattached to the flexure 212 to move the tongue 233 and the slider 232.Increasing the stroke of the motor 234 increases the rotational strokeof the DSA structure 214. In some embodiments, the stiffener 280 canincrease the stroke by over 70% (e.g., over embodiments of a similarflexure without the stiffener 280). As such, the presence andconfiguration (e.g., shape, elastic modulus) of the stiffener 280 can bebalanced with the mechanics of the flexure 212 to minimize bending ofthe motor 234 and flexure 212, maximize longitudinal stroke of the motor234, and/or reverse the bending profile of the motor 234.

As shown in FIGS. 20 and 21, the low modulus adhesive 282 deforms inshear during this actuation of the motor 234. While the profile of thestiffener 280 is matched to the profile of the motor 234 when the motor234 is not activated, as shown in FIG. 18, the motor 234 extends beyondthe lateral ends of the stiffener 280 in the embodiment of FIG. 20 asthe motor 234 expands such that the respective profiles of the stiffener280 and the motor 234 no longer match. In FIG. 20, the adhesive 282 isshown stretching between the relatively larger profile of the motor 234and the relatively smaller profile of the stiffener 280. In FIG. 21, theadhesive 282 is shown stretching between the relatively smaller profileof the motor 234 and the relatively larger profile of the stiffener 280.The relatively low elastic modulus of the adhesive 282 allows theadhesive 282 to stretch to accommodate the shear force generated by thechanges between the profiles of the stiffener 280 and the motor 234. Arelatively higher modulus adhesive 282 (not shown) may not deform inshear to the extent of a lower modulus adhesive, and may thereby reducethe amount of expansion of the motor 234 to reduce the stroke increaseprovided by the stiffener 280. Performance advantages can thereby beachieved by balancing the elastic modulus of the adhesive 282 and theelastic modulus of the stiffener 280. The elastic modulus of theadhesive 282 can be approximately 2000 times lower than the modulus ofthe material that forms the stiffener 280.

During actuation, the motor 234 may twist about the longitudinal axis ofthe motor 234 during actuation of the motor 234. Also, the stiffener 280may also be caused to twist about the longitudinal axis of the stiffener280 by the actuation of the motor 234. However, the presence of thestiffener 280 can limit the degree of twisting of the motor 234 aboutthe longitudinal axis of the motor 234. In some embodiments, because thetwisting can be caused by the resistance provided by the flexure 212, asdiscussed above, the presence of the stiffener 280 on the side of themotor 234 opposite the flexure 212 can reverse the direction of twist ascompared to an embodiment without the stiffener 280. As such, thepresence and configuration (e.g., shape, elastic modulus) of thestiffener 280 can be balanced with the mechanics of the flexure 212 tominimize twisting, maximize longitudinal stroke of the motor 234, and/orreverse the twisting profile of the motor 234.

FIGS. 22-24 are illustrations of a flexure 312 having a DSA structure314 with an asymmetric stiffener 380 in accordance with anotherembodiment of this disclosure. The flexure 312 is part of a DSAstructure 314 that can be similar to that of DSA structure 214 describedabove or other DSA structure referenced herein except where noted.Features of flexure 312 that are the same or similar to those of otherflexures are indicated by similar reference numbers. The gimbal 324 isshown with the motor 334 in a neutral or unactuated state in FIG. 22, acontracted actuated state in FIG. 23, and an expanded actuated state inFIG. 24. Stiffener 380 can be attached to motor 334 by adhesive 382. Asshown, the stiffener 380 has a central section 387 and a pair of armscomprising a first arm 388 and a second arm 389. A first arm 388 extendslaterally away from the central section 387 in a first direction (i.e.to the right and orthogonal relative to the longitudinal axis of thegimbal 324, parallel relative to the longitudinal axis of the motor334). A second arm 389 extends laterally away from the central section387 in a second direction (i.e. to the right and orthogonal relative tothe longitudinal axis of the gimbal 324, parallel relative to thelongitudinal axis of the motor 334) opposite the first direction.

The stiffener 380 is asymmetric about both of the length and width axesof the central section 387. For example, the first arm 388 extends alonga first longitudinal axis, the second arm 389 extends along a secondlongitudinal axis, and the first longitudinal axis is offset from thesecond longitudinal axis. As shown, the first arm 388 is proximalrelative to the second arm 389. The offset relationship of the first arm388 and the second arm 389 can mirror the offset relationship of thestruts 356. It is noted that while strut 356 is shown in FIGS. 22-24,the configuration of the struts 356 can be the same as the struts 56shown in FIG. 4B. For example, a first strut 356 on the right side ofthe flexure 312 can be proximal of the second strut 356 on the left sideof the flexure 312 while the first arm 388 on the right side of thestiffener 380 is proximal of the second arm 389 on the left side of thestiffener 380. The stiffener 380 can be between the struts 356 (e.g.,from a plan view perspective or along a plane that is coplanar with theflexure 312). The offset profile of the first arm 388 and the second arm389 corresponding to the offset profile of the struts 356 allows thefirst arm 388 to mechanically counteract the proximal strut 356 and thesecond arm 389 to mechanically counteract the distal strut 356. In someembodiments, the width of the first arm 388 is different (e.g., less)than the width of the second arm 389. In other embodiments (not shown),the stiffener has other asymmetrical shapes or is symmetric about thecentral section 387.

The stiffener 380 can provide sufficient stiffness to equally balanceand counteract the bending of the motor 334 as the motor 334 is expanded(e.g., as shown in FIG. 23) and contracted (e.g., as shown in FIG. 24).This action is provided at least in part because of the relatively lessamount of material, and therefore less stiffness (e.g., compared toembodiments with stiffeners such as 280 described above). The presenceand configuration (e.g., shape, elastic modulus, alignment with struts356) of the stiffener 380 can be balanced with the mechanics of theflexure 312 to minimize bending of the motor 334 and flexure 312,maximize longitudinal stroke of the motor 334, and/or reverse thebending profile of the motor 334. In one embodiment, the stiffener 380provides a stroke increase of approximately 30% over similar embodimentsof the flexure with no stiffener. Stiffener 380 also provides less twistalong the long axis of the motor 334 during actuation of the motor.Minimizing twist of the motor 334 can reduce excitation of flexureresonance modes by reducing motion of the flexure arms and traces.

Connectors 345 electrically and mechanically connect the motor 334 tothe flexure 312. More specifically, the connectors 345 make electricalconnections between traces of the flexure 312 and terminals of the motor334. The connectors 345 can further attach the motor 334 to the springarms 352. The slider 332 is mounted to a slider mounting of the tongue333. The slider mounting can be a surface of the tongue 333 to which theslider 332 can be attached, such as with an adhesive such as epoxy.Rotation of the tongue 333 by actuation of the motor 334 rotates theslider mounting, and thereby the slider 332, about a tracking axis.

FIG. 25 is detailed isometric view of the stainless steel side of thedistal end of a flexure 412 having a DSA structure 414 with a stiffener480 in accordance with another embodiment of this disclosure. FIG. 26 isa distal end view of the flexure 412 shown in FIG. 25. FIG. 27 is anillustration of the flexure 412 shown in FIG. 25 when the motor 434 isactuated into an expanded state. The flexure 412 is part of a DSAstructure 414 that can be similar to that of DSA structure 214 describedabove or other DSA structure referenced herein except where noted.Features of flexure 412 that are the same or similar to those of otherflexures are indicated by similar reference numbers. The flexure 412includes a gimbal 424. As shown, the stiffener 480 has a center section487 and a pair of opposite side sections 488 and 489. Each of the sidesections 488 and 489 are separated from the center section 487 byopenings 491. Each opening 491 is a void in the stiffener 480 thatextends from a first side of the stiffener 480 to a second side of thestiffener 480 opposite the first side. Each opening 491 is entirelybounded along the plane of the stiffener is lateral (i.e. left andright) as well as proximal and distal directions. Alternatively, anopening 491 can be open on any of the lateral, distal, and/or proximalsides. The stiffener 480 includes a reduced thickness region 484 at thecenter of the stiffener 480.

The stiffener 480 is attached to the motor 434 by a plurality ofadhesive layers 482 ₁-482 ₂. As shown, the plurality of adhesive layers482 ₁-482 ₂ are separate and do not contact one another. Each of theadhesive layers 482 ₁-482 ₂ can be a different type of adhesive suchthat each layer has a different elastic modulus. In the illustratedembodiment, for example, the center section 487 of the stiffener 480 isattached to the motor 434 by a first adhesive 482 ₁ and the sidesections 488 and 489 are attached by a second adhesive 482 ₂. The firstadhesive 482 ₁ can have a relatively low elastic modulus while thesecond adhesive 482 ₂ can have a relatively high elastic modulus suchthat the elastic modulus of the first adhesive 482 ₁ is lower than theelastic modulus of the second adhesive 482 ₂. The first adhesive 482 ₁can, for example, have the same properties as the adhesive 282 describedabove (e.g., by having an elastic modulus of around 100 MPa). The secondadhesive 482 ₂ can, for example, have an elastic modulus of about 2800MPa. Other stiffeners, and other adhesives including adhesives havingother elastic moduli, can be used and are within the scope of thisdisclosure. Since the second adhesive 482 ₂ is generally confined to thelateral sides of the motor 434, the higher elastic modulus of the secondadhesive 482 ₂ resists expansion and contraction over a relativelylimited length. As shown in FIG. 27, the second adhesive 482 ₂, having arelatively high modulus, does not shear to the degree that a relativelylower elastic modulus adhesive would (e.g., as shown in FIG. 20). Thesecond adhesive 482 ₂ remains relatively rigid and can cause an increasein bending of the motor 434 toward the stiffener 480 when the motor 434expands. The amount of stretch from the motor 434 is thereby enhanced,increasing the stroke (e.g., by amounts of 100% or more) over the strokeof similar gimbals without the stiffener 480.

Connectors 445 electrically and mechanically connect the motor 434 tothe flexure 412. More specifically, the connectors 445 make electricalconnections between traces of the flexure 412 and terminals of the motor434. The connectors 445 can further attach the motor 434 to the springarms 452. The slider 432 is mounted to a slider mounting of the tongue433. The slider mounting can be a surface of the tongue 433 to which theslider 432 can be attached, such as with an adhesive such as epoxy.Rotation of the tongue 433 by actuation of the motor 434 rotates theslider mounting, and thereby the slider 432, about a tracking axis.

FIG. 28 is detailed isometric view of the stainless steel side of thedistal end of a flexure 512 having a DSA structure 514 with a stiffener580 mounted on the motor 534. FIG. 29 is a detailed side view of thedistal end of the flexure 512 shown in FIG. 28. The flexure 512 is partof a DSA structure 514 that can be similar to that of DSA structure 214described above or other DSA structure referenced herein except wherenoted. Features of flexure 512 that are the same or similar to those ofother flexures are indicated by similar reference numbers. The flexure512 includes a gimbal 524. The stiffener 580 has multiple thicknesses.Specifically, the stiffener 580 has reduced thickness portions 593 atthe distal and proximal ends of the center section 587 and opposite sidesections 588 and 589. For example, the distal and proximal ends of thestiffener 580 are thinner than the middle of the stiffener 580. In thisway, the reduced thickness portions 593 extend along a perimeter of thestiffener 580. As shown, the sections of the stiffener 580 that bridgebetween the center section 587 and the side sections 588 and 589 have asmaller thickness with respect to the respective middles of the centersection 587 and the side sections 588 and 589. The stiffener 580 alsoincludes openings, such as opening 591. Multiple adhesives 582 ₁ and 582₂ are attached to the motor 534 and the stiffener 580. The adhesives 582₁ and 582 ₂ can be the same as or similar to the adhesives 482 ₁ and 482₂ described above. The adhesive 582 ₁ is underneath the center section587 and can have a lower elastic modulus than the adhesives 582 ₂ thatare underneath the side sections 588 and 589. Other embodiments (notshown) can have more than two sections each a having a differentthickness (e.g., three sections having different thicknesses) and/orother configurations of different thicknesses.

Connectors 545 electrically and mechanically connect the motor 534 tothe flexure 512. More specifically, the connectors 545 make electricalconnections between traces of the flexure 512 and terminals of the motor534. The connectors 545 can further attach the motor 534 to the springarms 552. The slider 532 is mounted to a slider mounting of the tongue533. The slider mounting can be a surface of the tongue 533 to which theslider 532 can be attached, such as with an adhesive such as epoxy.Rotation of the tongue 533 by actuation of the motor 534 rotates theslider mounting, and thereby the slider 532, about a tracking axis.

FIG. 30 is detailed isometric view of the stainless steel side of thedistal end of a flexure 612 having a DSA structure 614 with anasymmetric stiffener 680 attached to the motor 634 with multipleadhesives 682 ₁ and 682 ₂. The flexure 612 is part of a DSA structure614 that can be similar to that of DSA structure 214 described above orother DSA structure referenced herein except where noted. Features offlexure 612 that are the same or similar to those of other flexures areindicated by similar reference numbers. The flexure 612 includes agimbal 624. As shown, each side section 688 and 689 of the stiffener 680forms an “L” shape arm which includes a connecting section 693 thatextends laterally from the center section 687 and a longitudinal section694 that extends longitudinally (e.g., proximally or distally) from theend of the connecting section 693. As shown, the connecting sections 693extend orthogonal with respect to the center section 687 and thelongitudinal sections 694. Only a single connecting section 693 of thestiffener 680 extend between the center section 687 and eachlongitudinal section 694. As shown, a first one of the connectingsections 693 is proximal with respect to a second one of the connectingsections 693. The offset relationship of the connecting sections 693 canmirror the offset relationship of the struts 656. It is noted that whilestrut 656 is shown in FIG. 30, the configuration of the struts 656 canbe the same as the struts 56 shown in FIG. 4B. For example, a firststrut 656 on the right side of the flexure 612 can be proximal of thesecond strut 656 on the left side of the flexure 612 while a first oneof the connecting sections 693 on the right side of the stiffener 680 isproximal of a second one of the connecting sections 693 on the left sideof the stiffener 680. The stiffener 680 can be between the struts 656(e.g., from a plan view perspective or along a plane that is coplanarwith the flexure 612). The offset profile of the connecting sections 693corresponding to the offset profile of the struts 656 allows theconnecting sections 693 to respectively mechanically counteract thestruts 656. The asymmetric configuration of the stiffener 680 can reducetwist of the motor 634 during expansion and contraction. Portions ofcenter section 687 and longitudinal sections 694, and connectingsections 693, extend beyond the distal and proximal edges of the motor634 in the illustrated embodiment. In various other embodiments (notshown) the stiffener 680 entirely overlays the top surface of the motor634 and extends beyond the distal and/or proximal edges of the motor634. In still other embodiments (not shown) the stiffener 680 has stillother shapes and sizes with respect to the shape and size of the motor634.

Connectors 645 electrically and mechanically connect the motor 634 tothe flexure 612. More specifically, the connectors 645 make electricalconnections between traces of the flexure 612 and terminals of the motor634. The connectors 645 can further attach the motor 634 to the springarms 652. The slider 632 is mounted to a slider mounting of the tongue633. The slider mounting can be a surface of the tongue 633 to which theslider 632 can be attached, such as with an adhesive such as epoxy.Rotation of the tongue 633 by actuation of the motor 634 rotates theslider mounting, and thereby the slider 632, about a tracking axis.

FIG. 31 is an illustration of a flexure 712 having a DSA structure 714with an asymmetric stiffener 780 in accordance with another embodimentof this disclosure. The flexure 712 is part of a DSA structure 714 thatcan be similar to that of DSA structure 214 described above or other DSAstructure referenced herein except where noted. Features of flexure 712that are the same or similar to those of other flexures are indicated bysimilar reference numbers. The flexure 712 includes a gimbal 724. Astiffener 780 is attached to a motor 734 by adhesive 782 disposedbetween the stiffener 780 and the motor 734. As shown, the stiffener 780has a center section 787 and oppositely extending first arm 788 andsecond arm 789. The first arm 788 on one side of the stiffener 780 has asmaller width (i.e., in a direction of the longitudinal axis of theflexure 712) than the width of the second arm 789 on the other side ofthe stiffener 780. The first arm 788 can have a width of about one-halfthe width of the second arm 789. It will be understood that the relativewidths of the first and second arms 788 and 789 can be reversed suchthat second arm 789 can have a smaller width than the first arm 788.Similar embodiments can have other relative dimensions. Alternatively,the first and second arms 788 and 789 can have the same widths. It isalso noted that the first arm 788 is proximal with respect to the secondarm 789. The asymmetry of the stiffener 780 enables the DSA structure714 to have different bending characteristics on its opposite transversesides (i.e., with respect to a longitudinal axis). The offsetrelationship of the first and second arms 788 and 789 can mirror theoffset relationship of the struts 756. It is noted that while strut 756is shown in FIGS. 31-32C, the configuration of the struts 756 can be thesame as the struts 56 shown in FIG. 4B. For example, a first strut 756on the right side of the flexure 712 can be proximal of the second strut756 on the left side of the flexure 712 while a first arm 788 on theright side of the stiffener 780 is proximal of a second arm 789 on theleft side of the stiffener 780. The stiffener 780 can be between thestruts 756 (e.g., from a plan view perspective or along a plane that iscoplanar with the flexure 712). The offset profile of the first andsecond arms 788 and 789 corresponding to the offset profile of thestruts 756 allows the first and second arms 788 and 789 to respectivelymechanically counteract the struts 756.

FIGS. 32A and 32B are illustrations of the flexure 712 shown in FIG. 31when the motor 734 is actuated into contracted and expanded states,respectively. As shown, because of the relatively lower stiffnessprovided by the first arm 788 due to the second arm 789 being wider, theside of the flexure 712 with the first arm 788 bends more than the sideof the flexure 712 with the second arm 789. The amount of side-to-sidedifferential bending is related to the difference in stiffness betweenthe first and second arms 788 and 789. The rotational center of the DSAstructure 714 can be changed and tuned by the stiffener 780 by adjustingvarious variables, including the relative widths or thicknesses, andtherefore the relative stiffnesses, of the first and second arms 788 and789.

Connectors 745 electrically and mechanically connect the motor 734 tothe flexure 712. More specifically, the connectors 745 make electricalconnections between traces of the flexure 712 and terminals of the motor734. The connectors 745 can further attach the motor 734 to the springarms 752. The slider 732 is mounted to a slider mounting of the tongue733. The slider mounting can be a surface of the tongue 733 to which theslider 732 can be attached, such as with an adhesive such as epoxy.Rotation of the tongue 733 by actuation of the motor 734 rotates theslider mounting, and thereby the slider 732, about a tracking axis.

Flexures with DSA structures having stiffeners can provide importantadvantages. The stiffener changes the deformed shape of the PZT motorwhen the motor expands and contracts during operation. This shape changecan be tailored to increase the stroke amount of the actuator assembly,therefore achieving more stroke for the same input voltage to the motor.Alternatively, the same stroke can be maintained but with a lowervoltage as compared to embodiments without a stiffener. Anotheradvantage of the stiffener is that twist or asymmetric bending of themotor can be minimized by design of the stiffener. Increasing strokeperformance is an advantage in particular for co-located dual stageactuators since high stroke is difficult to achieve due to the inherentlow mechanical advantage when the motor is located close to the sliderthat the motor is moving. Due to low stroke, gimbal actuator designs mayrequire the use of more expensive multi-layer PZT motors as opposed tosimple single layer and lower cost motors. By increasing the strokeperformance, stiffeners can reduce the number of PZT motor layers neededfor a design and even allow for the use of single layer PZT motors toachieve stroke targets.

In some embodiments, the center of rotation of the motor, tongue, and/orslider can be adjusted by tailoring how the motor bends during actuationwith a stiffener. For example, the center of rotation can be located toextend through the dimple load point (e.g., where the dimple contactsthe stiffener). If the actuator's center of rotation is not locateddirectly at the dimple load point, then resonance performance may bereduced. The tailored stiffener designs, discussed above, can be used tomove the center of rotation by changing how the motor deforms.

The stiffener also provides a protective covering over the motor, whichmay otherwise be fragile. For example, the stiffener provides a pointupon which the dimple can press, wherein equivalent pressure from thedimple directly on the motor may damage the motor. The stiffener canprotect the motor surface from mechanical wear due to the dimple andshock loads at the dimple point. Shock loads will be distributed by thestiffener. The stiffener can also provide electrical insulation of themotor. For example, the loadbeam can serve as an electrical ground insome embodiments, and in such case the motor can be insulated fromelectrical connection through the dimple of the loadbeam by thestiffener. If the stiffener is formed from an electrically conductivemetal, then the adhesive layer between the stiffener and the motor canserve as electrical insulation.

While the use of a stiffener has been described in association withvarious gimbaled flexure embodiments, it is noted that a stiffener canbe used with any flexure referenced herein. For example, in theembodiment of FIG. 9-16C ₂, a stiffener can be positioned on the motor134 while the slider 132 can be attached to the stiffener (e.g., with anepoxy adhesive) and/or the slider 132 can be attached to the motor 134at a location not covered by the stiffener.

FIG. 33A is an isometric view of the trace side of flexure 812 having atwo-motor co-located DSA structure 814 with stiffeners 880. FIG. 33B isan isometric view of the stainless steel side of the flexure 812 (i.e.the opposite side with respect to FIG. 33A). The flexure 812, DSAstructure 814, or other component can be similar to that of any flexure,DSA structure, or other component described above or elsewherereferenced herein except where noted. Features that are the same orsimilar to those of other embodiments are indicated by similar referencenumbers. Flexure 812 can be formed by overlaying, in order, a stainlesssteel layer 840 (or other spring metal), polyimide or other dielectriclayer 842, copper or other conductive material layer 844, and coverlay846. The dielectric layer 842 generally electrically isolates structuresformed in the conductive material layer 844 from adjacent portions ofthe stainless steel layer 840. Coverlay 846 generally covers,electrically insulates, and protects the structures formed in theconductive material layer 844.

The gimbal 824 includes a base portion 850, spring arms 852, struts 856,and tongue 833. The base portion 850, spring arms 852, struts 856, andtongue 833 can each be formed from the stainless steel layer 840. Thespring arms 852 extend from the base portion 850. The tongue 833 issupported between the spring arms 852 by struts 856. Outer struts 856extend from the spring arms 852 inwardly to the proximal motor mountings858. The slider 832 can be attached to the tongue 833 at the slidermounting 854 (e.g., with adhesive) of the tongue 833. The proximal motormounting 858 serve as proximal mountings for the motors 834. Innerstruts 856 extend from the proximal motor mounting 858 inwardly toconnect with the tongue 833. In this way, the struts 856 and theproximal motor mounting 858 form linkages between the spring arms 852and the tongue 833. In some embodiments, the struts 856 are the onlypart of the stainless steel layer 840 that mechanically supports thetongue 833 between the spring arms 852. Specifically, the struts 856 canbe the only structural linkage between the spring arms 852 and thetongue 833, which may or may not include the proximal motor mounting 858as an intermediary between inner struts 856 (attached to the tongue 833)and outer struts 856 (attached to the spring arms 852). The flexiblecircuit 862, containing traces, may only minimally or negligiblymechanically support the tongue 833 as compared to the stainless steellayer 840. Also, the struts 856, in connecting with the tongue 833, canbe the only part of the stainless steel layer 840 that connects betweenthe spring arms 852 distal of the base portion 850. As shown, the struts856 can each be the narrowest part of the stainless steel layer 840 inan X-Y plane (as viewed from an overhead perspective) while thethickness of the stainless steel layer 840 can be consistent along theflexure 812. In the illustrated embodiments, the linkage portions formedby the struts 856 and proximal motor mountings 858 extend generallytransversely from a proximal portion of the tongue 833.

A pair of distal motor mountings 859 extend generally transversely orlaterally from the tongue 833 at locations spaced distally from theproximal motor mounting 858. The opposite ends of each of motors 834 areattached (e.g., by structural adhesive such as epoxy) to the proximalmotor mounting 858 and the distal motor mounting 859. While the proximalmotor mountings 858 are part of linkages between struts 856 connectingthe spring arms 852 to the tongue 833, and the distal motor mountings859 extend as tabs from the tongue 833, this arrangement can bereversed. For example, the distal motor mountings can be part oflinkages between struts connecting the spring arms 852 to the tongue 833while proximal motor mountings extend as tabs from the tongue 833. Otherconfigurations are also possible.

The motors 834 are arranged to have a parallel relationship. Forexample, each of the motors 834 has a longitudinal axis and thelongitudinal axes of the motors 834 extend parallel with each other, andparallel with the longitudinal axes of the slider 832 and the flexure812. As shown, the motors 834 are positioned on the flexure 812 onopposite lateral sides (e.g., left and right) of the slider 832.

A plurality of traces 860 are formed in the conductive material layer844 and extend between the base portion 850 and tongue 833 along theflexible circuit 862 formed in the dielectric layer 842. A number of thetraces 860 terminate at locations on a distal region on the tongue 833and are configured to be electrically attached to terminals of theread/write head (not shown) on the slider 832 to support read/writefunctions. Other traces 860 terminate at contacts (not shown) on thetongue 833, below or adjacent the motors 834, and are configured to beelectrically attached to terminals of the motors 834 to electricallyactivate the motors 834. Terminals can be on the tops and/or bottoms ofthe motors 834 and can be electrically connected to the traces viasolder or conductive adhesive, for example. Additional or otherelectrical connections to the motors 834 can be made by connecting theelectrical terminals of the motors 834 to the stainless steel layer 840,such as a grounding connection. In some other embodiment, the electricalconnections to the motors 834 can be made by other approaches andstructures (e.g., including approaches described herein in connectionwith other embodiments).

Stiffeners 880 can be structurally similar to any of those describedabove in connection with other embodiments (e.g., stiffeners 280) andcan be attached to the motors 834 using adhesive 882 or otherapproaches, as described above. As shown, the stiffeners 880 are mountedto free surfaces on the sides of the motors 834 (e.g., top sides)opposite the stainless steel layer 840. The stiffeners 880 canadditionally or alternatively be mounted to respective surfaces of themotors 834 that face the stainless steel layer 840. In such embodiments,the surface of the first or bottom side of each motor 834 is attached tothe flexure 812 (e.g., at both of the proximal motor mounting 858 andthe distal motor mounting 859) and the stiffeners 880 are also attachedto the surface of the first or bottom side of each motor 834.

The operation of gimbal 824 and DSA structure 814 is further describedwith reference to FIGS. 34A and 34B. FIG. 34A shows a plan view of theDSA structure 814 of FIGS. 33A-B in a neutral or unactuated state withno actuation drive signals applied to the motors 834. FIG. 34B shows aplan view of the DSA structure 814 of FIGS. 33A-B in a first actuatedstate. The motors 834 typically are orientated to have oppositearrangements such that a first polarity actuation drive signal isapplied to the anode terminal of one motor 834 and the cathode terminalof the other motor 834 such that one motor 834 expands while the othermotor 834 contracts. Such motor 834 expansion and contraction onopposite lateral sides of the flexure 812 rotates the slider mounting854 on the tongue 833 (and the slider 832 thereon) about a trackingaxis. Similarly, the tongue 833 can be rotated in the opposite directionby the application of a second polarity actuation drive signal to themotors 834. For example, FIG. 34B shows the right motor 834 expanding,including expansion along a lengthwise direction, while the left motor834 contracts, including contraction along the lengthwise direction.Such movement pivots the tongue 833 off of the spring arms 852 via theexpanding and contracting motors 834 attached to the proximal motormounting 858 and the distal motor mounting 859. The rotational trackingmotion of the tongue 833 is facilitated by the struts 856 bending. Whilethe struts of previous embodiments are offset, the inner and outerstruts 856 are laterally aligned and located at the same position alonga longitudinal axis of the flexure 812, respectively.

Out-of-plane bowing, twisting, and/or asymmetric bending can be presentupon activation of the motors 834 as discussed and illustrated herein.However, the stiffeners 880 can limit or reverse the bending of themotor 834 and/or gimbal 824 during activation as discussed herein. Forexample, the stiffeners 880 can balance or counteract the stiffness ofthe flexure 812 about the motor 834 to control or limit verticaldeflection. The stiffeners 880 can substantially reduce bending of themotors 834 during the actuation strokes. Stroke efficiency of the DSAstructure 814 can be increased substantially (e.g., by 15-75%) usingstiffeners 880. Adhesive 882 can deform (e.g., in shear) between thestiffeners 880 and motors 834 as discussed above. Multiple types ofadhesives may be applied under stiffeners 880, as discussed in theprevious embodiments. The multiple types of adhesives may have differentproperties, such as different elastic moduli under different areas ofeach stiffener 880.

The stiffeners 880 shown in FIGS. 33A and 33B have a shape and expansethat are the same as the surface of the motors 834 on which thestiffeners 880 are mounted. For example, the stiffeners 880 entirelycover the top sides of the motors 834. In other embodiments, stiffenerscan have different sizes, shapes, and thicknesses (e.g., as describedabove), and the sizes, shapes, and thicknesses of the stiffeners can betailored to provide specific and desired mechanical effects on thebending that might otherwise be produced by the motors 834.

FIG. 35A is an isometric view of the trace side of flexure 912 having atwo-motor co-located DSA structure 914. FIG. 35B is an isometric view ofthe stainless steel side of the flexure 912 (i.e. the opposite side withrespect to FIG. 35A) with stiffeners 980 mounted on the motors 934. Theflexure 912, tongue 933, DSA structure 914, or other component can besimilar to that of any flexure, DSA structure, or other componentdescribed above or elsewhere referenced herein except where noted.Features that are the same or similar to those of other embodiments areindicated by similar reference numbers.

The flexure 912 includes a gimbal 924. The motors 934 are mounted on thegimbal 924. As shown, motors 934 are mounted to the proximal motormounting 958 and the distal motor mounting 959. While the motors 834 andslider 832 are mounted on the same side of the flexure 812 in theembodiment of FIGS. 33A-B, the motors 934 and slider 932 are mounted onopposite sides of the flexure 912 in the embodiment of FIGS. 35A-B.Besides the mounting of the motors 934 and slider 932 on opposite sidesof the flexure 912, the components of the embodiment of FIGS. 35A-B mayhave the same configuration as those of the embodiment of FIGS. 33A-B.

FIG. 36A is an isometric view of the trace side of flexure 1012 having atwo-motor co-located DSA structure 1014. FIG. 36B is an isometric viewof the stainless steel side of the flexure 1012 (i.e. the opposite sidewith respect to FIG. 36A) with stiffeners 1081 mounted on the motors1034. FIG. 37 is an isometric view of the trace side of the flexure 1012but with the motors 1034 removed to show additional detail. The flexure1012, DSA structure 1014, or other component can be similar to that ofany flexure, DSA structure, or other component described above orelsewhere referenced herein except where noted. Features that are thesame or similar to those of other embodiments are indicated by similarreference numbers.

Flexure 1012 can be formed by overlaying, in order, a stainless steellayer 1040 (or other spring metal), polyimide or other dielectric layer1042, copper or other conductive material layer 1044, and coverlay 1046.The flexure 1012 includes a gimbal 1024. Motors 1034 are mounted on thegimbal 1024. The gimbal 1024 includes spring arms 1052, struts 1056, andtongue 1033. The spring arms 1052, struts 1056, and tongue 1033 can eachbe formed from the stainless steel layer 1040. The slider mounting 1054,which is part of the tongue 1033, is supported between the spring arms1052 by struts 1056. Outer struts 1056 extend from the spring arms 1052inwardly to the proximal motor mounting 1058. The slider 1032 can beattached to the tongue 1033 at the slider mounting 1054 (e.g., withadhesive). The proximal motor mountings 1058 serve as proximal mountingsfor the motors 1034. Inner struts 1056 extend from the proximal motormountings 1058 inwardly to connect with the tongue 1033. In this way,the struts 1056 and the proximal motor mountings 1058 form linkagesbetween the spring arms 1052 and the tongue 1033. In some embodiments,the struts 1056 are the only part of the stainless steel layer 1040 thatconnects or otherwise supports the tongue 1033 between the spring arms1052. Specifically, the struts 1056 can be the only structural linkagebetween the spring arms 1052 and the tongue 1033. Also, the struts 1056,in connecting with the tongue 1033, can be the only part of thestainless steel layer 1040 that connects between the spring arms 1052distal of the base portion 1050. As shown, the struts 1056 can each bethe narrowest part of the stainless steel layer 1040 in an X-Y plane (asviewed from an overhead perspective) while the thickness of thestainless steel layer 1040 can be consistent along the flexure 1012. Inthe illustrated embodiments, the linkage portions formed by the struts1056 and proximal motor mounting 1058 extend generally transversely froma proximal portion of the tongue 1033.

A pair of distal motor mountings 1059 extend generally transversely orlaterally from the tongue 1033 at locations spaced distally from theproximal motor mounting 1058. The distal motor mountings 1059 can betabs that extend from the tongue 1033. The opposite ends of each ofmotors 1034 are attached (e.g., by structural adhesive such as epoxy) tothe proximal motor mounting 1058 and the distal motor mounting 1059 onthe same side of the flexure 1012 as the slider 1032. Electricalactivation of the motors 1034 can move the slider 1032 along a trackingaxis as discussed herein (e.g., in the manner shown in FIGS. 34A-B).While the proximal motor mountings 1058 are part of linkages betweenstruts 1056 connecting the spring arms 1052 to the tongue 1033, and thedistal motor mountings 1059 extend as tabs from the tongue 1033, thisarrangement can be reversed. For example, the distal motor mountings canbe part of linkages between struts connecting the spring arms 1052 tothe tongue 1033 while proximal motor mountings extend as tabs from thetongue 1033.

In various embodiments shown above, stiffeners are entirely located onthe motors, usually only on one surface of each motor, and are notconnected with other elements (e.g., other than adhesive bonding thestiffeners to the motors). However, as shown in FIGS. 36B and 37,stiffeners 1081 can be a part of, or otherwise attach to, otherelements. As shown, the stiffeners 1081 are tabs that extend from theflexure 1012. More specifically, the stiffeners 1081 are formed from thestainless steel layer 1040. The stiffeners 1081 branch from the tongue1033. Each stiffener 1081 is attached to the tongue 1033 by a connector1083. Each connector 1083 is a part of the stainless steel layer 1040.As shown, the connectors 1083 can be narrower than the tongue 1033 andthe stiffeners 1081. The narrowing of the connectors 1083 may allowflexing of the connectors 1083 between the stiffeners 1081 and thetongue 1033. The connectors 1083 branch from the tongue 1033 atrespective locations between the proximal motor mounting 1058 and thedistal motor mounting 1059. Likewise, the stiffeners 1081 are locatedbetween the proximal motor mounting 1058 and the distal motor mounting1059. The stiffeners 1081 are attached to the motors 1034 by adhesive1082 between the stiffeners 1081 and the motors 1034. For example, alayer of adhesive 1082 can attach to the surfaces of the sections of thestainless steel layer 1040 that form the stiffeners 1081 and can furtherattach to surfaces of the motors 1034 that face the flexure 1012. Thestiffeners 1081 have a generally oval shape. Stiffeners 1081 can haveother shapes, sizes, and thicknesses tailored to reduce or otherwisecontrol the bending of the motors 1034. The stiffeners 1081 cansubstantially reduce bending of the motors 1034 and bending of theflexure 1012 during the actuation strokes as discussed herein.

The motors 1034 are located on the same side of the flexure 1012 (e.g.,the trace side, opposite the stainless steel layer 1040 side) as theslider 1032. The stiffeners 1081 are located on the surface of eachmotor 1034 that faces the flexure 1012. The motors 1034 do not havestiffeners on the side of the motors 1034 that face away from theflexure 1012 (e.g., the stainless steel layer 1040 specifically) in theembodiment shown in FIGS. 36A-37, however stiffeners, as disclosedherein, could be provided on these sides of the motors 1034 asalternatives to, or in addition to, the stiffeners 1081 shown.

FIG. 38A is an isometric view of the trace side of flexure 1112 having atwo-motor co-located DSA structure 1114. FIG. 38B is an isometric viewof the stainless steel side of the flexure 1112 (i.e. the opposite sidewith respect to FIG. 38A) with stiffeners 1181 mounted on the motors1134. The flexure 1112, DSA structure 1114, or other component can besimilar to that of the flexures, the DSA structure, or other componentdescribed above or elsewhere referenced herein except where noted.Features that are the same or similar to those of other embodiments areindicated by similar reference numbers.

The flexure 1112 includes a stainless steel layer 1140. The flexure 1112includes a gimbal 1124. Motors 1134 are mounted on the gimbal 1124. Asshown, the motors 1134 are mounted to the proximal motor mounting 1158and the distal motor mounting 1159 on the side of the tongue 1133opposite the slider 1132. While the motors 1034 and slider 1032 aremounted on the same side of the flexure 1012 in the embodiment of FIGS.36A-37, the motors 1134 and slider 1132 are mounted on opposite sides ofthe flexure 1112 in the embodiment of FIGS. 38A-B. Besides the mountingof the motors 1134 and slider 1132 on opposite sides of the flexure1112, the components of the embodiment of FIGS. 38A-B may have the sameconfiguration as the embodiment of FIGS. 36A-37.

Any of the embodiments presented herein can be modified in view of thefeatures presented in any of commonly owned U.S. patent application Ser.No. 14/026,427, entitled CO-LOCATED GIMBAL-BASED DUAL STAGE ACTUATIONDISK DRIVE SUSPENSIONS, filed Sep. 13, 2013, U.S. patent applicationSer. No. 14/044,238, entitled CO-LOCATED GIMBAL-BASED DUAL STAGEACTUATION DISK DRIVE SUSPENSIONS WITH MOTOR STIFFENERS, filed Oct. 2,2013, and U.S. patent application Ser. No. 13/972,137, entitledCO-LOCATED GIMBAL-BASED DUAL STAGE ACTUATION DISK DRIVE SUSPENSIONS WITHOFFSET MOTORS, filed Aug. 21, 2013, each of which is incorporated hereinby reference in its entirety. Likewise, any of the embodiments presentedin such applications can be modified with any of the features of thepresent disclosure.

Although the present invention has been described with reference topreferred embodiments, those skilled in the art will recognize thatchanges can be made in form and detail without departing from the spiritand scope of the invention. For example, although described inconnection with certain co-located DSA structures, stiffeners andassociated features described herein can be used in connection withmotors on other DSA structures, including other co-located DSAstructures. Furthermore, while various example embodiments have beenprovided to demonstrate various features, these are not the exclusiveembodiments contemplated. As such, any embodiment can be modified with afeature of any other embodiment.

The following is claimed:
 1. A dual stage actuation flexure comprising: a flexure comprising a gimbal, the gimbal comprising a pair of spring arms, a tongue between the spring arms, and a pair of linkages respectively connecting the pair of spring arms to the tongue; a pair of motors mounted on the gimbal; a pair of stiffeners respectively mounted on the motors, each stiffener bonded to the motor on which the stiffener is mounted by a respective layer of adhesive that is between the motor and the stiffener; and a slider mounting, wherein electrical activation of the motors bends the pair of linkages to move the slider mounting about a tracking axis while the stiffeners limit the degree of bending of the motors during the electrical activation.
 2. The dual stage actuation flexure of claim 1, wherein the tongue comprises a pair of first motor mountings, the pair of motors respectively attached to the first motor mountings.
 3. The dual stage actuation flexure of claim 2, wherein the pair of linkages comprises a pair of second motor mountings, the pair of motors respectively attached to the pair of second motor mountings.
 4. The dual stage actuation flexure of claim 1, wherein each linkage of the pair of linkages comprises a strut, and electrical activation of the motor bends the struts to move the slider mounting about the tracking axis.
 5. The dual stage actuation flexure of claim 1, wherein each linkage of the pair of linkages comprises an outer strut extending inward from a respective one of the pair of arms and an inner strut extending outward from the tongue, each of the inner and outer struts connecting with a respective one of a pair of motor mountings located respectively between the spring arms and the tongue, the motors respectively attached to the pair of motor mountings.
 6. The dual stage actuation flexure of claim 1, wherein the pair of stiffeners are respectively stiffer than the portions of the gimbal on which the motors are respectively mounted.
 7. The dual stage actuation flexure of claim 1, wherein each stiffener limits the degree of bending of the motor on which the stiffener is mounted during electrical activation of the motor.
 8. The dual stage actuation flexure of claim 1, wherein each motor bends in a first direction when the motor is activated to expand and the motor bends in a second direction, opposite the first direction, when the motor is activated to contract.
 9. The dual stage actuation flexure of claim 1, wherein each stiffener limits the degree of twisting of a respective one of the pair of motors during activation of the motors.
 10. The dual stage actuation flexure of claim 1, wherein each stiffener comprises a layer of metal.
 11. The dual stage actuation flexure of claim 1, wherein each stiffener comprises a layer of polymer.
 12. The dual stage actuation flexure of claim 1, wherein each stiffener is only in contact with the adhesive that bonds the motor to the stiffener.
 13. The dual stage actuation flexure of claim 1, wherein the layer of adhesive has an elastic modulus of about 100 MPa.
 14. The dual stage actuation flexure of claim 1, wherein the layer of adhesive has an elastic modulus that is about 2000 times lower than the elastic modulus of the stiffeners.
 15. The dual stage actuation flexure of claim 1, wherein each stiffener is bonded to the motor on which the stiffener is mounted by a plurality of adhesive layers including the respective layer of adhesive, each adhesive layer of the plurality of adhesive layers formed from a different type of adhesive and located underneath a different area of the stiffener.
 16. The dual stage actuation flexure of claim 15, wherein each adhesive layer of the plurality of adhesive layers has a different elastic modulus.
 17. The dual stage actuation flexure of claim 1, further comprising an additional pair of stiffeners respectively mounted on the motors, wherein the pair of stiffeners is respectively mounted on the top sides of the motors and the additional pair of stiffeners is respectively mounted on the bottom sides of the motors.
 18. The dual stage actuation flexure of claim 1, wherein each stiffener comprises a tab extending from the tongue.
 19. The dual stage actuation flexure of claim 1, wherein the slider mounting and the pair of motors are located on the same side of the flexure.
 20. The dual stage actuation flexure of claim 1, wherein the slider mounting is located on a first side of the flexure while the pair of motors are located on a second side of the flexure opposite the first side.
 21. The dual stage actuation flexure of claim 1, wherein at least one of the stiffeners is asymmetric with respect to one or both of a longitudinal axis of the stiffener and a transverse axis of the stiffener.
 22. The dual stage actuation flexure of claim 1, wherein each stiffener entirely covers a side of the motor on which the stiffener is mounted.
 23. The dual stage actuation flexure of claim 1, wherein each stiffener does not entirely cover a side of the motor on which the stiffener is mounted.
 24. A dual stage actuation flexure comprising: a flexure comprising a pair of spring arms, a pair of struts, and a tongue between the spring arms; a pair of motors mounted on the flexure, each motor comprising a top side and a bottom side opposite the top side; a pair of stiffeners respectively mounted on the top sides of the motors, wherein the bottom sides of the motors face the flexure; adhesive located between the stiffeners and the motors and bonded to the stiffeners and the motors; and a slider mounting, wherein electrical activation of the motors bends the pair of struts to move the slider mounting while the stiffeners limit the degree of bending of the motors during the electrical activation.
 25. The dual stage actuation flexure of claim 24, wherein each stiffener is only in contact with the adhesive.
 26. The dual stage actuation flexure of claim 24, wherein the motors are at least partially mounted on the spring arms.
 27. A dual stage actuation flexure comprising: a flexure; a pair of motors mounted on the flexure; a pair of stiffeners respectively mounted on the motors; adhesive located between the stiffeners and the motors and bonded to the stiffeners and the motors, each stiffener mounted over a single side of the motor on which the stiffener is mounted, each stiffener only in contact with the adhesive; and a slider mounting, wherein electrical activation of the motors moves the slider mounting while the stiffeners limit the degree of bending of the motors during the electrical activation.
 28. A dual stage actuation flexure comprising: a flexure comprising a gimbal, the gimbal comprising a pair of spring arms, a tongue between the spring arms, and a pair of linkages respectively connecting the pair of spring arms to the tongue; a pair of motors mounted on the gimbal; a pair of stiffeners respectively mounted on the motors, each stiffener stiffer than the portion of the gimbal on which the respective motor and stiffener are mounted; and a slider mounting, wherein electrical activation of the motors bends the pair of linkages to move the slider mounting about a tracking axis while the stiffeners limit the degree of bending of the motors during the electrical activation. 